The construction of the Crossrail project began at North Dock in Canary Wharf in May 2009. With the railway due to open in 2018, it is one of the largest single infrastructure investments undertaken in the UK to date. It consists of 21 kilometres of new twin-bore tunnels and 10 new world-class stations in central London connecting to upgraded lines providing new services to the east and west of the UK capital. Crossrail Project: Infrastructure Design and Construction - Volume 4 contains a collection of 23 papers submitted to Crossrail's Technical Papers Competition. Contributions have come from consultants, contractors, suppliers and third-party stakeholders all of whom have been involved in the Crossrail project. The papers cover a variety of disciplines including health and safety, insulation materials, material corrosion, ground engineering and many more. As part of the legacy of the Crossrail project, it is important for the organisation to share its experiences and best practices with the rest of the industry and to showcase the skills of the personnel involved and the successful delivery of each phase of works. This fourth volume continues Crossrail's dissemination of that experience. Crossrail Project: Infrastructure Design and Construction - Volume 4 provides a valuable source of reference for current practices in design and construction of large-scale underground projects.